Application Research Of Active Disturbance Rejection Control In Variable Frequency Control Of Marine Main Seawater Pump

When the heat load is satisfied,the speed of the main seawater pump is controlled by frequency conversion,which can save a lot of energy.The choice of frequency conversion control method plays a vital role in the control of low temperature fresh water temperature.Therefore,this paper studies and improves the frequency conversion control method of the main seawater pump,and uses vector control as the control strategy of the drive motor.The defects of the proposed method are improved,and the results are verified through simulation experiments.The specific work of this article is as follows:Firstly,the heat balance analysis of the ship cooling water system is carried out,and the mathematical model of the ship cooling water system is established by referring to the relevant data,mainly including the cylinder liner heat exchanger model,the pipeline hydraulic model,the three-way valve mathematical model,the central cooler mathematical model,the seawater pump The speed calculation model is composed.The cooling water system' can calculate the required speed of the seawater pump as the input of the asynchronous motor vector control according to the change of the host thermal load and the temperature of the seawater.Secondly,the mathematical model of the three-phase asynchronous motor is established,and the state transformation in the two-phase rotating coordinate system is converted by coordinate transformation,and the vector control mode of the asynchronous motor oriented by the rotor magnetic field is determined.In general,the speed loop,flux linkage loop and current loop of asynchronous motor vector control adopt PI controller.This control method causes the performance of the controller to decline when the changing conditions and motor parameters change.Combined with the basic vector control principle,the design Four first-order auto disturbance rejection controllers are used as vector-controlled speed loop,flux linkage loop,d-axis current loop,q-axis current loop.The auto disturbance rejection controller estimates and compensates for load disturbances and changes in motor parameters.It can greatly improve the robustness of vector control.Finally,for the problem of many parameters of the auto disturbance rejection controller and the difficulty of tuning,it is proposed that on the basis of the empirical tuning method,an artificial bee colony algorithm is used to autotune the key parameters of the auto disturbance rejection controller,and the parameters are reduced by this method.The difficulty of setting,improve the control effect of the controller..In order to verify the correctness of the theory and method mentioned in this paper,simulation verification was performed in Simulink.The simulation results show that the model can automatically adjust the flow of the seawater pump to maintain the stability of the low-temperature freshwater temperature when the host load and seawater temperature change.Compared with PI-based vector control,ADRC-based vector control has better robustness in the case of load disturbance and parameter changes.Using artificial bee colony algorithm to adjust the parameters of the active disturbance rejection controller,the performance.of the controller has been improved to a certain extent.